The present invention relates to bag discharge systems and, more particularly, to a bulk bag discharge system and method that minimizes contamination transferred to the bag contents.
Bulk bags are used in many industries to transport large quantities of products, such as pharmaceuticals, bulk chemicals, and food products. Bulk bag applications in the food industry are generally non-sanitary, which means that microbial growth, especially salmonella, botulism, and certain molds, are not expected. This is the case with sugar, salt, flour, flavorings, and baking soda which are commonly handled food ingredients that do not require sanitary equipment.
However, there are several materials, particularly meat and dairy products, which lend themselves to use with bulk bags that would require sanitary discharge equipment. For example, dairy and meat products must meet sanitary standards as defined by the United States Department of Agriculture, because they harbor bacteria or mold spores that can become active and multiply if provided with adequate moisture, temperature, and time.
Bulk bags are typically made from woven polyester, polypropylene, or other polymer, and can typically hold up to about 2,000 pounds. The dimensions are typically 42".times.42".times.42", with an 18-inch diameter spout that is about 16 inches long at the bottom center. An inner disposable plastic liner not attached to the bag is often used as a boundary to moisture and dirt, allowing the bag to be reused by providing a different inner plastic liner for each subsequent use. Sometimes, such liners are provided attached to the inside of the bag. Generally, the bag has four loops, one in each corner at the top of the bag, that are used to lift and transport the bulk bag with a lifting device such an overhead hoist or forklift.
The bag is generally filled through a fill spout located in the top of the bag. The fill spout is secured, such as by tying a cord around the spout, after the fill is completed. Discharge requires lifting the bag, pulling a bottom spout down and away from the bag, and untying or cutting a tie that secures the bottom spout. Once the tie is removed, the bag spout is opened and the inner liner is pulled down. Upon untwisting, untying, or unknotting the liner, solids will flow down by gravity and out of the bag.
Known bulk bag discharge systems have a lack of sanitation when the contents of the bag are discharged, because contaminants on the outside and the bottom of the bag (e.g., dirt, insects, loose threads, rodent feces, hair, etc.) fall into the discharge system and become entrained in the clean product exiting the bag spout. Known bag dischargers also have no provision for quick disassembly or easily cleaned components that allow routine cleaning and elimination of microbial growth, exacerbating the sanitation problem. Because of these sanitation problems with known bulk bag dischargers, none have been certified as approved by the United States Department of Agriculture for use in sanitary applications with dairy or meat products, nor do they comply with the Dairy Industry 3A standards of sanitation.
It is desirable to provide a bulk bag discharger and discharging system that comply with sanitary standards established by the United States Department of Agriculture and the Dairy Industry 3A standards of sanitation to allow the use of bulk bags in applications for foods, such as dairy and meat products, that are required to be maintained in sanitary conditions, It would also be desirable to provide a bulk bag discharge system that is quickly disassembled and easily cleaned such that microbial growth would be discouraged to aid in maintaining a suitable level of sanitary conditions for use with foods, etc., requiring sanitary conditions.